Rechargeable batteries may be used in multiple applications, ranging from portable music devices, to mobile phones, to electric vehicles. Batteries are constructed from individual battery cells, for example one or more lithium ion cells either in parallel or series configuration. Batteries also have a small printed circuit board, PCB, containing a mandatory safety controller, for example a safety circuit, to protect the cells against excess voltage, current, temperature. Furthermore the battery has connections from anode and cathode. The battery has also connections towards the system battery. From an integration point of view, the construction is not space efficient and may consume a lot of critical physical space within the device.